Substituted sulfonate antidote compounds and method of use with herbicides

ABSTRACT

New compounds corresponding to the formula: 
     
         X--(CH.sub.2).sub.n --O--SO.sub.2 --R 
    
     wherein X can be halogen, R can be selected from the group consisting of alkyl, haloalkyl, halogen, acetoxyalkyl, acetoxy haloalkyl, aryl and substituted aryl, and n can be a whole number ranging between 1 and 5. The compositions described herein are used to protect corn from injury by thiolcarbamate herbicides.

This application is a continuation-in-part of copending application,Ser. No. 68,529, filed Aug. 31, 1970 and a division of Ser. No. 100,770,filed Dec. 22, 1970, both now abandoned.

BACKGROUND OF THE INVENTION

Among the many herbicidal compounds commercially available, theN,N-dialkyl thiolcarbamate herbicides alone or mixed with otherherbicides such as triazines have reached a relatively high degree ofcommercial success. These herbicides are immediately toxic to a largenumber of weed pests at different concentrations varying with theresistance of the weeds mentioned. Some examples of these compounds aredescribed and claimed in U.S. Pat. Nos. 2,913,327, 3,037,853, 3,175,897,3,185,720 and 3,198,786. It has been found in practice that the use ofthe thiolcarbamates as a herbicide in corn fields sometimes causesserious injury to the corn plants. When used in the recommended amountsin the soil to control many broadleaf weeds and grasses, seriousmalformation and stunting of the corn plants results. This abnormalgrowth in the corn plants results in loss of crop yield.

DESCRIPTION OF THE INVENTION

It has been discovered that corn plants can be protected against injuryby the thiolcarbamates of the above-noted U.S. Patents by adding to thesoil an antidote composition having the following formula:

    X--(CH.sub.2).sub.n --O--SO.sub.2 --R

wherein X can be halogen, R can be selected from the group consisting ofalkyl, haloalkyl, halogen, acetoxyalkyl, acetoxy haloalkyl, aryl andsubstituted aryl, and n can be a whole number from 1 to 5.

The compounds represented by the above formula can be synthesized bymixing together an appropriate alcohol with an appropriate sulfonylchloride. A solvent such as ethyl ether can be used, if desired. Then,an acid acceptor such as triethylamine is added to the mixture.Essentially quanitative yields of the end product are obtained.

In order to illustrate the merits of the present invention, reference ismade to the following examples:

EXAMPLE 1 2-Bromoethyl methanesulfonate

A mixture of 12.5 ml. of 2-bromoethanol, 7.6 ml. of methanesulfonylchloride and 100 ml. of ether was formed. Then, 14 ml. of triethylaminewas added dropwise over a 55 minute period to the formed solution at5°-10°C. and stirred for 1 hour at 5°-10°C. The mixture was then allowedto stand at room temperature and was stirred for another 15 minutes. Tothe mixture was added 100 ml. of water, the ether layer separated, driedover magnesium sulfate and evaporated to yield 16 grams of a very lightyellow oil. n_(D) ³⁰ 1.4801.

EXAMPLE 2 2-Bromoethyl ethanesulfonate

A mixture containing 12.5 ml. of 2-bromoethanol, 12.9 ml. of ethanesulfonyl chloride and 100 ml. of ether was formed. Then, 14 ml. oftriethylamine was added dropwise over a 55 minute period at 5°-10°C. andstirred for 1 hour. The mixture was allowed to come to room temperatureand stirred for an additional 15 minutes. To the mixture was added 100ml. of water, the ether layer was separated, dried over magnesiumsulfate and evaporated to yield 17.6 grams of a yellow oil. n_(D) ³⁰1.4760.

EXAMPLE 3 3-Bromopropyl methanesulfonate

A mixture containing 13.9 ml. of 3-bromo-1-propanol, 7.6 ml. of methanesulfonyl chloride and 100 ml. ether was formed. The mixture was mixedtogether and 14 ml. of triethylamine was added over a period of 45minutes at 5°-10°C. and then stirred at 5°-10°C. for 1 hour. The mixturewas allowed to come to room temperature and was stirred for anadditional 15 minutes. To the mixture was added 100 ml. of water and theether solution dried over magnesium sulfate and evaporated to yield 14.5g. of a colorless oil. n_(D) ³⁰ 1.4749.

EXAMPLE 4 2-Chloroethyl isobutane-sulfonate

A mixture was formed containing 6.7 ml. of ethylene chlorohydrin, 70 ml.of ether and 15.6 g. of isobutane sulfonyl chloride. Then, 14 ml. oftriethylamine was added dropwise to the mixture with stirring in an icebath over a period of 30 minutes at 12°-14°C. While stirring the mixturewas allowed to warm to 23°C. (1 hour) and was then washed with water(100 ml.), dried over magnesium sulfate and evaporated to yield 19.7 g.of a colorless oil. n_(D) ³⁰ 1.4502.

Other compounds were prepared in an analogous manner starting with theappropriate starting materials as outlined above. The following is atable of compounds representative of those embodied by the presentinvention. Compound numbers have been assigned to them and are used foridentification throughout the balance of the specification.

                  TABLE I                                                         ______________________________________                                        X--(CH.sub.2 .sub.n --O--SO.sub.2 --R                                         Compound                                                                      Number  n         X         R                                                 ______________________________________                                         1      2         Br        CH.sub.3                                           2      2         Br        C.sub.2 H.sub.5                                    3      3         Br        CH.sub.3                                                                      CH.sub.3                                                                      |                                         4      2         Cl        CH.sub.2 --CH                                                                 |                                                                    CH.sub.3                                                                      CH.sub.3                                                                      |                                         5      3         Br        CH.sub.2 --CH                                                                 |                                                                    CH.sub.3                                                                      CH.sub.3                                                                      |                                         6      2         Br        CH.sub.2 --CH                                                                 |                                                                    CH.sub.3                                           7      2         Br                                                           8      2         Br        (CH.sub.2).sub.3 CH.sub.3                          9      2         Cl        CH.sub.3                                                                      O                                                                             ∥                                        10      2         Br        CH.sub.2 --C--O--CH.sub.2 --CH.sub.2 --Br         11      2         Br        CH.sub.2 Cl                                       12      2         Br        (CH.sub.2).sub. 5 CH.sub.3                        13      3         Br        CH.sub.2 Cl                                       14      3         Br        (CH.sub.2).sub.5 CH.sub.3                         15      2         Cl        OCH.sub.2 CH.sub.2 Cl                             16      2         Br        Cl                                                17      4         Br        CH.sub.3                                          18      2         Br                                                          19      2         I         CH.sub.3                                          20      2         Br        CH.sub.2 CH.sub.2 CH.sub.2 Cl                     ______________________________________                                    

The compositions of this invention were tested in the following manner.

Test 1: Soil Incorporation

Metal flats measuring 8 × 12 × 3 inches in area were filled with 10 lbs.of Felton loamy sand soil. The herbicide and herbicide antidote wereapplied separately or in combination to the soil as it is mixed in afive-gallon cement mixer. The following stock solutions were made up ofeach compound when the herbicide and antidote were applied separately.In making the stock solutions of the herbicide, 936 mg. of 75.5 % activeingredient was diluted with 100 ml. of water. For the antidote, 700 mg.of technical material was diluted with 100 ml. of acetone. One ml. ofthese stock solutions is equivalent to 7 mg. active ingredient or onepound per acre when this treated soil was placed into 8 × 12 × 3 inchflats. After the soil was treated with the herbicide and the antidote atthe desired rates, the soil was transferred from the cement mixer backinto 8 × 12 × 3 inch flats where it was now ready for planting cornseed. A pint sample of soil was then removed from each flat and retainedfor covering the seeds after planting. The soil was leveled and rowsone-half inch deep were made in each flat. Enough DeKalb XL 374 cornseeds were planted to obtain good stands in each treatment. Seeds werethen covered up with the one pint of soil which had been removed justprior to planting.

The flats were then placed on greenhouse benches where temperatures werebetween 70°-90°F. The flats were watered by sprinkling as needed toassure good plant growth until rated. The crop tolerance was rated aftertwo or three weeks. The results of these tests are set forth in TableII.

Test 2: Corn Seed Treatment

Metal flats measuring 8 × 12 × 3 inches in area were filled with 10 lbs.of Felton loamy sand soil. Soil incorporated herbicides were applied atthis time. The soil from each flat was placed into a five-gallon cementmixer where the soil was mixed as the herbicides were applied as a stocksolution by adding 936 mg. of 75.5% active ingredient to 100 ml. ofwater. One ml. of stock solution was applied to the soil in a volumetricpipet for each pound of herbicide desired. One ml. of stock solutioncontains seven mg. of herbicide which equals one pound per acre whenapplied to soil in 8 × 12 × 3 inch flats. After the herbicideincorporation, the soil was placed back into the flats.

Flats of herbicide-treated and untreated soil were then ready to beplanted. A pint sample of soil was then removed from each flat andplaced next to each flat for later use in covering up the seeds. Thesoil was leveled and rows one-half inches deep were made for plantingseeds. Alternating rows of treated and untreated crop seeds were sown.In each test six DeKalb XL 374 field corn seeds were planted in eachrow. Rows were approximately 11/2 inches apart in the flat. Seedtreatment was applied by placing 50 mg. of the seed treatment compoundwith 10 grams of corn seed in a suitable container and shaking themuntil the seeds were uniformly covered with the seed treatment. Seedtreatment compounds were applied as liquid slurries and powder or dusttreatments. In some cases acetone was used to dissolve powdered or solidcompounds so they could be more effectively applied to the seeds.

After flats were seeded they were covered with the one pint of soilwhich had been removed just prior to planting. Flats were placed ongreenhouse benches where temperatures ranged from 70°-90°C. Flats werewatered by sprinkling as needed to assure good plant growth. Percentcontrol ratings were taken two to three weeks after treatments wereapplied.

In each test, the herbicide is applied alone, in combination with theseed protectant and the seed protectant is applied alone to check forphytotoxicity. The results of these tests are tabulated in Table III. Itshould be noted that Run Nos. 7 thru 10 were carried out in styrofoamflats measuring 5 × 7 × 23/4 inches with all other conditions remainingthe same.

                                      TABLE II                                    __________________________________________________________________________    Herbicide        Rate                                                                              Compound No. 1                                                                         Compound No. 2                                                                         Compound No. 3                                                                         Injury to Corn                                 lb/A                                                                              lb/A     lb/A     lb/A     %                             __________________________________________________________________________    EPTC*            6   1                          30 ST MF                      EPTC*            6   10                         10 ST                         EPTC*            6   100                        90 ST                         EPTC*            6            1                 50 ST MF                      EPTC*            6            10                20 ST                         EPTC*            6                     1        40 ST MF                      EPTC*            6                     10       10 ST                         EPTC*            6                              98  MF                                             1                          10 ST                                              10                         20 ST                                              100                        90 ST                                                       1                  0                                                          10                20 ST                                                                1         0                                                                   10       10 ST                         EPTC*            3   1                           0                            EPTC*            3   10                         20 ST                         EPTC*                                           98   MF                       EPTC* +          6+                                                           2-Chloro-4-ethylamino-6-                                                       isopropylamino-s-triazine                                                                     1   1                          10   MF                       EPTC* +          6+                                                           2-Chloro-4-cyclopropylamino-                                                   6-isopropylamino-1,3,5-                                                       triazine        1   1                           0                            EPTC + 2,4-dichlorophenoxy-                                                    acetic acid     3+11/2                                                                            1                          20 ST                         EPTC + 2,4-dichlorophenoxy-                                                    acetic acid     3+11/2                                                                            0                          75 ST MF                      S-propyl dipropylthiocarbamate                                                                 6   1                          10   MF                       S-propyl dipropylthiocarbamate                                                                 6   0                          98   MF                       S-ethyl cyclohexylethyl-                                                       thiocarbamate   6   1                          25   MF                       S-ethyl cyclohexylethyl-                                                       thiocarbamate   6   0                          90   MF                       S-ethyl diisobutylthiocarbamate                                                                12  2                           0                            S-ethyl diisobutylthiocarbamate                                                                12  1                           0                            S-ethyl diisobutylthiocarbamate                                                                12  0                          75   MF                       __________________________________________________________________________     ST = Stunt;                                                                   MF = Malformation                                                             *EPTC = S-ethyl-N,N-dipropylthiolcarbamate                               

                  TABLE III                                                       ______________________________________                                                         Percent Injury to Corn                                       Run  Com-    EPTC    Seed    Treated                                                                              Untreated Seed                            No.  pound   lb/A    Treatment                                                                             Seed   in Adjacent Row                                No.             % W/W                                                    ______________________________________                                        1    1       6       0.5     90 ST  20 ST MF                                  2    2       6       0.5     50 ST  20 ST MF                                  3    3       6       0.5     25 ST  30 ST MF                                  4    1       --      0.5     90 ST   0                                        5    2       --      0.5     50 ST   0                                        6    3       --      0.5     20 ST   0                                        7    1       6       0.005   75 MF  94   MF                                   8    1       6       0.05    13 ST  15 ST MF                                  9    1       --      0.005    0      0                                        10   1       --      0.05    23 ST   0                                        ______________________________________                                         ST = Stunt;                                                                   MF = Malformation                                                        

The antidote compounds of the present invention can be used in anyconvenient form. Thus, the antidote compounds can be made intoemulsifiable liquids, emulsifiable concentrates, liquid, wettablepowder, powders, granular or any other convenient form. In its preferredform, the antidote compounds are admixed with the N,N-dialkylthiolcarbamates and incorporated into the soil prior to or afterplanting the corn seed. It is to be understood, however, that thethiolcarbamate herbicide can be incorporated into the soil andthereafter the antidote compound can be incorporated into the soil.Moreover, the corn seed can be treated with the antidote compound andplanted into the soil which has been treated with herbicides oruntreated with the herbicide and subsequently treated with theherbicide. The addition of the antidote compound does not affect theherbicidal activity of the carbamate compounds.

The amount of antidote composition present can range between about 0.01to about 15 parts by wt. per each part by wt. of thiolcarbamateherbicide. The exact amount of antidote compound will usually bedetermined on economic ratios for the most effective amount usable.

What is claimed is:
 1. In the method of controlling weeds wherein aherbicide is added to the habitat thereof, said herbicide containing aneffective amount of a mixture of a thiocarbamate and a triazine, theimprovement comprising adding to the habitat thereof from 0.01 to about15 parts by weight for each part by weight of the herbicide mixture, anantidote compound represented by the formula: ##EQU1##